function subquad(f,j,exact)
subplot(3,2,j);
title(['f' num2str(j)])
for i = 1:30
    r(i)=romberg(f,i);
    g(i)=gauss(f,i);
    c(i)=clenshaw_curtis(f,i);
end
hold on
grid on
set(gca,'YScale','log')
plot(abs((g-exact)/exact),'ko','MarkerFaceColor','k')
plot(abs((c-exact)/exact),'ro')
plot(abs((r-exact)/exact),'+')
hold off